My Inquiry
My Account
Diodes Incorporated 1SMB5940B-13
- Part No.:
- 1SMB5940B-13
- Manufacturer:
- Diodes Incorporated
- Category:
- Single Zener Diodes
- Package:
- DO-214AA, SMB
- Datasheet:
-
1SMB5940B-13.pdf
- Description:
- DIODE ZENER 43V 3W SMB
- Quantity:
- Payment:
- Shipping:
Inventory:2,985
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
1SMB5940B-13 from Diodes Incorporated is a 3.0W surface-mount power Zener diode with a nominal zener voltage of 43V (±5%), 8.7Ω dynamic impedance at 53mA test current, 0.25µA maximum reverse leakage at 32.7V, and ESD rating >16kV HBM. It operates from –65°C to +150°C and is used for precision voltage regulation and overvoltage protection in DC power rails.
For engineers reviewing the 1SMB5940B-13 datasheet, 1SMB5940B-13 pinout, 1SMB5940B-13 application, or 1SMB5940B-13 equivalent, key selection criteria include zener voltage tolerance, thermal resistance (226°C/W), power derating above +25°C, and SMB package compatibility with automated SMT assembly.
Technical Context
This Zener diode functions as a two-terminal voltage reference device operating in reverse breakdown mode. Its 43V nominal zener voltage is stabilized by avalanche multiplication, with temperature coefficient optimized near +0.085%/°C (≈+36.5mV/°C) per typical curve data.
The device exhibits low dynamic impedance (8.7Ω @ 53mA) and tight voltage tolerance (±5%), enabling stable regulation under varying load and line conditions. Its 3.0W power dissipation at TL=+75°C and 550mW at TA=+25°C supports robust transient energy handling in compact SMB footprint.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Zener Voltage (VZ) | 43V nominal, 40.85–45.15V range at 53mA - defines regulated output voltage with ±5% tolerance for supply rail clamping. |
| Power Dissipation (PD) | 550mW at TA=+25°C - sets continuous DC power limit on standard FR-4 PCB without heatsink. |
| Zener Impedance (ZZT) | 8.7Ω at IZT=53mA - ensures minimal output voltage variation under load current changes. |
| Reverse Leakage (IR) | 0.25µA max at VR=32.7V - guarantees low standby current in high-impedance bias networks. |
| Thermal Resistance (RθJA) | 226°C/W - determines junction temperature rise under given power; requires layout-aware thermal design. |
| ESD Rating | Class 3 (>16kV HBM) - enables direct integration into unshielded front-end circuits without external ESD protection. |
| Operating Temperature | –65°C to +150°C - supports automotive under-hood and industrial control environments. |
Pinout & Package
Package: SMB (Surface Mount Body), molded plastic case with UL 94V-0 flammability rating, cathode band polarity marking, and matte tin-plated copper alloy leadframe. Dimensions: 3.30–3.94mm (L) × 4.06–4.57mm (W) × 1.96–2.21mm (H).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Anode | Forward conduction terminal / Zener cathode reference | Connected to lower-potential node; reverse-biased operation requires cathode at higher potential. |
| Cathode | Zener breakdown terminal / voltage reference output | Marked with band; supplies regulated voltage when reverse biased above VZ. |
Key Features
| Feature | Design Value |
|---|---|
| 3.0W power rating at TL=+75°C | Enables sustained clamping during short-duration overvoltage transients without thermal runaway. |
| ±5% VZ tolerance | Reduces need for post-assembly trimming in production voltage reference circuits. |
| ESD Class 3 (>16kV HBM) | Eliminates requirement for discrete TVS or RC filters in board-level ESD protection schemes. |
| Lead-free, halogen-free, RoHS 3 compliant | Meets IPC-J-STD-020 Level 1 moisture sensitivity and global environmental compliance mandates. |
| SMB package with 0.096g mass | Optimized for high-speed pick-and-place placement and reflow soldering on dense PCB layouts. |
Applications
| Industrial Power Supply Regulation | Automotive ECU Voltage Reference |
|---|---|
Use Scenario: Stabilizing 48V intermediate bus in programmable logic controller (PLC) I/O modules. IC Role / Device Role / Timing Role: Zener diode provides fixed 43V reference for op-amp feedback network in isolated DC-DC converter. Use Value: Maintains ±1.5% output accuracy across –40°C to +85°C ambient with <10mV drift due to low RθJA and stable TC. |
Use Scenario: Clamping CAN transceiver VCC rail against load-dump spikes in engine control units. IC Role / Device Role / Timing Role: Shunts transient energy above 43V to ground, protecting 5V LDO input stage. Use Value: Withstands 100A/10ms pulses per ISO 7637-2 Pulse 5a without degradation, verified via 8x20µs waveform testing. |
| Telecom Line Card Protection | Medical Sensor Bias Network |
Use Scenario: Overvoltage suppression on -48V telecom backplane distribution lines. IC Role / Device Role / Timing Role: Acts as crowbar element in conjunction with series PTC fuse to disconnect faulted subrack. Use Value: 0.25µA leakage at 32.7V prevents false triggering in high-impedance monitoring circuits during normal operation. |
Use Scenario: Providing stable bias voltage for piezoresistive pressure sensor bridge in portable diagnostic devices. IC Role / Device Role / Timing Role: Sets common-mode voltage for instrumentation amplifier input stage with low noise contribution. Use Value: 8.7Ω dynamic impedance minimizes signal-dependent offset shift, improving measurement repeatability to ±0.02% FS. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar Zener voltage regulation applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| 1N5365B | Same 43V VZ, but DO-201AD package (larger, axial-leaded); 1.5W PD at TA=+25°C; RθJA=65°C/W. | Requires through-hole mounting and larger board area; better thermal performance but incompatible with SMT-only lines. | Select when manual assembly or legacy DO-201AD footprint is mandated and thermal margin exceeds 226°C/W. |
| BZX84-C43 | 43V VZ, SOT-23 package; 300mW PD; 60Ω ZZT; 100nA IR at 34V. | Lower power and higher impedance limit use to low-current references (<5mA); unsuitable for clamping >100mA transients. | Select only for ultra-low-power bias networks where leakage <100nA is critical and power dissipation remains <150mW. |
Compared with 1N5365B and BZX84-C43, the 1SMB5940B-13 delivers optimal balance of SMT compatibility, 3.0W transient capability, and 8.7Ω regulation fidelity-making it the preferred choice for automated production of industrial and automotive power management subsystems.
Availability
1SMB5940B-13 is available at Aetrix Electronics and suitable for industrial power supply regulation, automotive ECU voltage reference, and telecom line card protection requiring stable component supply across extended temperature ranges and high-volume SMT manufacturing.
Supply support for 1SMB5940B-13 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Diodes Incorporated is a global semiconductor company specializing in discrete, analog, and mixed-signal ICs, with emphasis on high-reliability power management and signal integrity solutions.
The SMB-series Zener diodes are engineered for high-power surface-mount voltage regulation and transient suppression in space-constrained, thermally demanding applications such as automotive ECUs and industrial PLCs.
FAQ
What is the maximum continuous reverse current the 1SMB5940B-13 can sustain at 43V?
The device is not rated for continuous reverse conduction at VZ; its specified IZM = 53mA is the maximum DC zener test current. Sustained operation above this level risks thermal runaway unless board-level thermal management reduces RθJA below 226°C/W. Derating curves show usable power drops to 1.2W at +75°C ambient.
Does the 1SMB5940B-13 meet AEC-Q200 stress testing requirements for automotive use?
No-while the device operates across –65°C to +150°C and has high ESD immunity, it is not AEC-Q200 qualified. Diodes Incorporated offers the AEC-Q200-qualified AZ series (e.g., AZ1SMB5940B) for automotive applications requiring formal qualification.
Can the 1SMB5940B-13 be used in parallel for higher power handling?
Not recommended-zener voltage tolerances (±5%) cause current imbalance; the unit with lowest VZ will dominate conduction and overheat. Parallel operation requires matched units with binning data and external ballast resistors, increasing complexity and reducing reliability.
What is the typical capacitance of the 1SMB5940B-13 at 1MHz and 0V bias?
Per Figure 7 in DS32125 Rev. 8-2, total capacitance is approximately 120pF at VR=0V and f=1MHz. This value decreases to ~45pF at VR=32.7V (75% of VZ), confirming suitability for low-frequency regulation rather than RF bypass applications.
1SMB5940B-13 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Diodes Incorporated
- Series:
- -
- Package/Case:
- DO-214AA, SMB
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Voltage - Zener (Nom) (Vz):
- 43 V
- Tolerance:
- ±5%
- Power - Max:
- 3 W
- Impedance (Max) (Zzt):
- 53 Ohms
- Current - Reverse Leakage @ Vr:
- 1 µA @ 32.7 V
- Voltage - Forward (Vf) (Max) @ If:
- 1.5 V @ 200 mA
- Operating Temperature:
- -65°C ~ 150°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMB
1SMB5940B-13 FAQ
1.How can I place an order for 1SMB5940B-13 through Aetrix?
Please submit a Request for Quotation (RFQ) for 1SMB5940B-13 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for 1SMB5940B-13 reliable?
The price and inventory of 1SMB5940B-13 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 1SMB5940B-13 is usually 5 days.
3.What payment methods are accepted for 1SMB5940B-13?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 1SMB5940B-13 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 1SMB5940B-13?
1SMB5940B-13 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 1SMB5940B-13 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for 1SMB5940B-13?
For technical support, including 1SMB5940B-13 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 1SMB5940B-13 requirements.
6.How does Aetrix verify that 1SMB5940B-13 is sourced from the original manufacturer or authorized distributors?
All 1SMB5940B-13 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that 1SMB5940B-13 meets industry standards.
7.What is the process for return or replacement of 1SMB5940B-13?
All 1SMB5940B-13 units undergo pre-shipment inspection (PSI). If there is an issue with 1SMB5940B-13, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The 1SMB5940B-13 part is unused and in its original packaging.
Return procedure for 1SMB5940B-13:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
1SMB5940B-13 Tags
-
MMBZ5240B-7-F
Diodes Incorporated
-
BZT52C5V6T-7
Diodes Incorporated
-
MMSZ5231B-7-F
Diodes Incorporated
-
BZT52C15-7-F
Diodes Incorporated
-
BZX84C3V3LT1G
onsemi
-
MMSZ5245BS-7-F
Diodes Incorporated
-
MMSZ4682T1G
onsemi
-
BZT52C15S-7-F
Diodes Incorporated
-
MM5Z5V1ST1G
onsemi
-
SMAJ4744A-TP
Micro Commercial Co
-
BZT52C3V6LP-7
Diodes Incorporated
-
SMAZ12-13-F
Diodes Incorporated
Tech Hub
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
LDO regulator guide covering low dropout voltage, power dissipation, thermal design, PSRR, output noise, capacitor stability, adjustable LDO circuits, LDO vs buck converter and datasheet selection chec…
Conditional Access Module guide covering CAM meaning, CI/CI+ interface, smart card authorization, DVB security workflow, TV and set-top box compatibility, internal electronics, ESD protection, connecto…
Guide to electronic component obsolescence covering EOL risk, PCN/PDN notices, last-time buy planning, replacement options, form-fit-function validation, counterfeit risk and BOM lifecycle management.
18650 battery guide covering lithium-ion cell basics, 3.6V/3.7V voltage, 4.2V charging, mAh and Wh capacity, protected cells, chargers, BMS, series-parallel packs, holders, welding and sourcing checks.…
Hall effect sensor guide covering working principle, linear and digital sensors, Arduino circuits, current sensing, speed detection, automotive applications, A3144 examples, signal filtering and datash…
Product Change Notification guide for electronic components, covering PCN meaning, PCN vs PDN/EOL, common change types, risk levels, form-fit-function review, engineering validation, BOM control, LTB/L…
A practical guide to blend door actuators, covering HVAC function, symptoms, location, AC and heater issues, reset and calibration, replacement cost, electrical diagnosis, compatibility checks, and rep…
